package com.gzsxy.JUC.forkjoin;

import java.util.concurrent.ExecutionException;
import java.util.concurrent.ForkJoinPool;
import java.util.concurrent.ForkJoinTask;
import java.util.stream.LongStream;

public class Test {
    public static void main(String[] args) throws ExecutionException, InterruptedException {

        test2();
    }

    //普通方法   8s
    public static void test1() {
        Long sum = 0L;
        long start = System.currentTimeMillis();

        for (Long i = 1L; i <= 10_0000_0000; i++) {
            sum += i;
        }
        long end = System.currentTimeMillis();
        System.out.println("sum=" + sum + "时间：" + (end - start));
        ;
    }

    //使用forkjoin  7s
    public static void test2() throws ExecutionException, InterruptedException {
        long start = System.currentTimeMillis();

        ForkJoinPool forkJoinPool = new ForkJoinPool();
        ForkJoinTask<Long> task = new ForkJoinDemo(0L, 10_0000_0000L);
        ForkJoinTask<Long> submit = forkJoinPool.submit(task);//提交任务

        Long sum = submit.get();   //获取返回
        long end = System.currentTimeMillis();
        System.out.println("sum=" + sum + "时间：" + (end - start));
        ;
    }


    //  stream 并行流  2s
    public static void test3() {
        long start = System.currentTimeMillis();

        //stream 并行流  rangeClosed递加   parallel并行计算  reduce返回结果
        long sum = LongStream.rangeClosed(0L, 10_0000_0000L).parallel().reduce(0, Long::sum);


        long end = System.currentTimeMillis();
        System.out.println("sum=" + sum + "时间：" + (end - start));
        ;
    }

}
